Time-controlled keyhole guard



Nov. 4, 1924. 1,513,895

R. DE VIVO TIME CONTROLLED KEYHOLE GUARD Filed May 22. 1923 Fig. l-

Q) I Q l 36 667mg? 14 I N V EN TOR.

A TTORNE Y.

Patented Nov. 4, 1924.

UNITED STATES ROBERT DE VIVQ, OF SARATOGA SEB/INGS. NEW YORK.

TIME-CONTROLLED KEYHGLE GUARD.

Application filed May 22,

T 0 all whom it may concern.

Be it known that 1, ROBERT DE Vrvo, a subject of the King of Italy, residing at Saratoga Springs, in the county of Saratoga and State of New York, have invented certain new and useful Improvements in Time- Controlled Keyhole Guards, of which the following is a specification.

My invention relates to time controlled keyhole guards, and the object thereof is to provide a simple, inexpensive device for preventing the introduction of a key into a lock for a desired period of time; a device which is operated by a clock mechanism;

' which may be readily adjusted so as to guard the lock for any desired period of time within the range of the device; and which after the elapse of the period of time for which it may have been adjusted, will stop and leave the keyhole accessible.

The manner in which I accomplish my object is illustrated in the accompanying drawings, in which:

Fig. 1 is an elevation of my device, dial cover plate omitted.

Fig. 2 is a top plan view, dial cover plate in section, door and lock indicated in dotted lines.

The same reference characters refer to the same parts throughout the several views.

Referring to the drawings, which are in a certain sense illustrative only, it will be seen that my device comprises a base plate 2, on one end of which is mounted a spring operated train of gears, or clock mechanism 3, provided with the usual winding stem 4.

A slow moving gear wheel 5, operated by a clock mechanism 3, or forming a part thereof, engages with a gear wheel 6, pivoted on a stud 7, projecting fro-m the base plate 2. Fastened to the gear wheel 6, so that it will move as an integral part thereof, is a pinion 8, meshing with the teeth on the toothed disc 9, pivoted at 10, to the base plate 2.

The plate 2, has formed therethro-ugh a keyhole 12, adapted to pass the key which fits the lock the device is adapted'to guard. A similar keyhole is formed through the toothed disc or dial plate 9, and projecting from the face of said dial plate is a pin 14, adapted to contact with the stop 15, and block the movement of the dial plate when the keyhole 12, therethrough comes into alignment with the keyhole in the plate 2.

1923. Serial No. 640,764.

The keyhole in the plate 2, is to be in alignment with the keyhole in the lock which the device is to guard, so that when the pin 14, contacts with the stop 15, and blocks further movement of the dial plate 9, (and the clock mechanism by which it is being actuated), the keyhole in said dial plate will be stopped in exact alignment with the keyhole through the plate 2, and the keyhole of. the lock the device has been guarding will then re main accessible until the device is again adjusted.

Suitable indicia, as the numerals 1 to 7 0 and the division lines which they identify, are provided to facilitate the accurate setting of the dial plate so that the keyhole 12, will be out of alignment with the keyhole in the lock for the desired period of time. A sight hole 16, in the dial cover plate 17, exposes the indicia at a point adjacent the stop 15, the numeral which appears under the sight hole indicating the length of time which must elapse before the keyhole 12, comes into the aligned position where the key will pass.

On the gear wheel 6, I form a knob 19, provided with a recess in which I arrange a spring 20, adapted to normally hold the gear 6, in mesh with the gear 5.

In order to adjust the dial plate 9, it is only necessary to draw the knob 19, forward against the tension of the spring 20, until the gear 6, is out of engagement with the gear 5, (as indicated by dotted lines in Fig. 2), and then turn it in the direction indicated by the dart thereon until the dial plate has been rotated to carry the pin 14, away from the stop 15, a distance which will require the desired lapse of time for the spring operated mechanism 3, to produce a reverse rotation sufficient to again force the pin 14, against the stop 15.

Other means than the spring 20, may be utilized to hold the gear 6, normally in mesh with the gear 5, and a frame of suit able shape may be substituted for the back plate 2, and dial cover plate 17.

A device constructed substantially as illustrated and described, is comparatively simple and inexpensive, and well adapted to prevent the introduction of a key into a lock for a variable period of time, and may be easily and quickly adjusted to vary such period of time; and at any time after the lapse of the period of time for which it was adjusted, will permit free access to the look. What;' I claim as new and desire to secure by Letters Patent is? o In a device of the class described, a frame; a toothed disc, I with a key hole therethrough and a pin projecting v therefrom;-

pivoted on said frame; a stop adapted. to prevent complete rotation" of said disc; a

gear Wheel driven by a'clockmechanism; a 10 second gear Wheel, wlth a pinion fastened engaged from said driven gear Wheel so as 23 to permit cofinter rotation of said second gear wheehpinion, and toothed disc.

In testimony whereof I have afi'ixed my signature.

ROBERT DE VIVO. 

